“…In the MIEC cathode, the cathode reaction takes in the entire surface of the MIEC cathode material, not just confined to the TPBs formed by LSM, electrolyte, and pores as in the LSM cathode [10]. These MIEC oxides, including (La,Sr)CoO 3 ·(LSC) [11][12][13], (La,Sr)(Co,Fe)O 3 ·(LSCF) [14,15], (Sm,Sr)Co 3 ·(SSC) [16][17][18][19], (Ba,Sr)(Co,Fe)O 3 ·(BSCF) [20], and GdBaCoO 5 + ␦ [21,22] have been demonstrated very high electrochemical performance. Besides Cocontaining MIECs which have received considerable attention, a few other new cathode materials have been developed, including pyrochlore oxides [23][24][25][26][27], Ruddlesden-Popper type oxides [28][29][30][31][32][33][34], LaNi 1 − x Fe x O 3 ·(LNF) based oxides [35,36].…”